רב לכם בני לוי. דָּבָר גָּדוֹל אָמַרְתִּי לָכֶם; וְלֹא טִפְּשִׁים הָיוּ, שֶׁכָּךְ הִתְרָה בָהֶם וְקִבְּלוּ עֲלֵיהֶם לְקָרֵב? הֵם חָטְאוּ עַל נַפְשׁוֹתָם, שֶׁנֶּאֱמַר "אֵת מַחְתּוֹת הַחַטָּאִים הָאֵלֶּה בְּנַפְשֹׁתָם" (במדבר י״ז:ג׳), וְקֹרַח שֶׁפִּקֵּחַ הָיָה מָה רָאָה לִשְׁטוּת זֶה? עֵינוֹ הִטְעַתּוּ, רָאָה שַׁלְשֶׁלֶת גְּדוֹלָה יוֹצְאָה מִמֶּנּוּ — שְׁמוּאֵל שֶׁשָּׁקוּל כְּנֶגֶד מֹשֶׁה וְאַהֲרֹן — אָמַר בִּשְׁבִילוֹ אֲנִי נִמְלָט, וְכ"ד מִשְׁמָרוֹת עוֹמְדוֹת לִבְנֵי בָנָיו, כֻּלָּם מִתְנַבְּאִים בְּרוּחַ הַקֹּדֶשׁ, שֶׁנֶּאֱמַר "כָּל אֵלֶּה בָנִים לְהֵימָן" (דברי הימים א כ"ה ה'), אָמַר אֶפְשָׁר כָּל הַגְּדֻלָּה הַזֹּאת עֲתִידָה לַעֲמֹד מִמֶּנִּי וַאֲנִי אֶדּוֹם? לְכָךְ נִשְׁתַּתֵּף לָבֹא לְאוֹתָהּ חֲזָקָה, שֶׁשָּׁמַע מִפִּי מֹשֶׁה שֶׁכֻּלָּם אוֹבְדִים וְאֶחָד נִמְלָט, "אֲשֶׁר יִבְחַר ה' הוּא הַקָּדוֹשׁ" — טָעָה וְתָלָה בְעַצְמוֹ, וְלֹא רָאָה יָפֶה, לְפִי שֶׁבָּנָיו עָשׂוּ תְשׁוּבָה, וּמֹשֶׁה הָיָה רוֹאֶה. — תַּנְחוּמָא: רב לכם בני לוי means, “It is a great (an important) thing that I have told you, ye sons of Levi”). But were they not fools in that although he so sternly warned them they nevertheless undertook to offer! They, however, sinned against their own souls (i.e., they were regardless of their lives) as it is said, (17:3) “the censers of these sinners against their souls”. — But Korah who certainly was a clever (lit., open-eyed) man, what reason had he to commit this folly? His mind’s eye misled him. He saw by prophetic vision a line of great men (more lit., a great chain) descending from him, amongst them the prophet Samuel who was equal in importance to Moses and Aaron together (cf. Psalms 99:6: משה ואהרן בכהניו ושמואל בקראי שמו), and he said to himself, “On his account I shall escape the punishment”. And he further saw twenty-four Mishmars (shifts of Levites who formed the Temple Choir) arising among his grand-children, all of them prophesying by the Holy Spirit, — as it is said, (I Chronicles 25:5) “All these (prominent musicians) were sons of Heiman” (Heiman was a descendant of Korah; cf. I Chronicles 6:18—23). — He said, “Is it possible that all this dignity is to arise from me and I shall remain silent (be myself of no importance)?” On this account he joined the others in order to attain to that prerogative, because he had indeed heard from the mouth of Moses that all else of them would perish and one would escape: "He whom the Lord will choose will be holy". He mistakenly applied this to himself. But he had not seen correctly, for his sons repented of their rebellious attitude and therefore did not die at that time (cf. Numbers 26:11), and it was from them that Samuel and the Levitical singers were descended. Moses, however, foresaw this. (Midrash Tanchuma, Korach 5).

רב לכם. דָּבָר גָּדוֹל נְטַלְתֶּם בְּעַצְמְכֶם לַחֲלֹק עַל הַקָּבָּ"ה: רב לכם means, a great responsibility have you taken upon yourselves in rebelling against the Holy One, blessed be He.